Airport security went through big changes after 9/11. These were the biggest ones

Twenty-five years after hijackers took control of four commercial aircraft and turned them into weapons, air travel security has been reshaped in ways that few other industries matched. In the wake of Sept. 11, responsibilities expanded and systems became more standardized, including federalized airport security, tougher cockpit protection, and passenger and baggage screening. The process has continued to evolve over the past two and a half decades as technology improved and new aviation-aligned attack methods emerged. Each change has been designed to counter threats in real time, reflecting how the modern airline security workflow differs sharply from what existed at the start of the century.